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A Derivation of Faraday's law from Coulomb's Law and Relativity

Started byKuan Peng <titang78@gmail.com>
First post2026-01-14 22:45 +0000
Last post2026-01-30 18:33 +0000
Articles 9 on this page of 69 — 6 participants

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  A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-14 22:45 +0000
    Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-15 09:20 +0100
      Re: A Derivation of Faraday's law from Coulomb's Law and Relativity x <x@x.net> - 2026-01-15 13:12 -0800
      Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-15 22:20 +0000
        Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-16 08:22 +0100
          Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-16 11:50 +0000
            Re: A Derivation of Faraday's law from Coulomb's Law and Relativity "Paul B. Andersen" <relativity@paulba.no> - 2026-01-16 22:18 +0100
              Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-17 11:58 +0000
            Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-17 15:13 +0100
              Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-17 20:34 +0000
                Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-18 05:28 +0100
                  Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-18 19:11 +0000
                    Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-18 23:48 +0100
                    Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-18 23:50 +0100
                      Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-19 20:51 +0000
                        Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-19 22:03 +0100
                          Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-20 12:01 +0000
                            Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-20 15:08 +0100
                              Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-20 19:43 +0000
              Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-18 04:03 +0100
            Re: A Derivation of Faraday's law from Coulomb's Law and Relativity ram@zedat.fu-berlin.de (Stefan Ram) - 2026-01-18 18:46 +0000
              Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-20 12:16 +0000
                Re: A Derivation of Faraday's law from Coulomb's Law and Relativity ram@zedat.fu-berlin.de (Stefan Ram) - 2026-01-20 13:13 +0000
                  Re: A Derivation of Faraday's law from Coulomb's Law and Relativity ram@zedat.fu-berlin.de (Stefan Ram) - 2026-01-20 14:39 +0000
                    Re: A Derivation of Faraday's law from Coulomb's Law and Relativity ram@zedat.fu-berlin.de (Stefan Ram) - 2026-01-20 15:02 +0000
                    Re: A Derivation of Faraday's law from Coulomb's Law and Relativity ram@zedat.fu-berlin.de (Stefan Ram) - 2026-01-20 15:26 +0000
                  Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-20 19:58 +0000
                    Re: A Derivation of Faraday's law from Coulomb's Law and Relativity ram@zedat.fu-berlin.de (Stefan Ram) - 2026-01-20 20:58 +0000
                      Re: A Derivation of Faraday's law from Coulomb's Law and Relativity ram@zedat.fu-berlin.de (Stefan Ram) - 2026-01-20 21:00 +0000
                      Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-21 20:27 +0000
                        Re: A Derivation of Faraday's law from Coulomb's Law and Relativity ram@zedat.fu-berlin.de (Stefan Ram) - 2026-01-21 21:20 +0000
                          Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-22 13:35 +0000
                            Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-23 13:19 +0100
                              Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-24 06:37 +0100
                              Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-24 17:37 +0100
                              Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-26 11:03 +0000
                                Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-26 15:12 +0100
                  Re: A Derivation of Faraday's law from Coulomb's Law and Relativity ram@zedat.fu-berlin.de (Stefan Ram) - 2026-01-22 13:07 +0000
                Re: A Derivation of Faraday's law from Coulomb's Law and Relativity John Hasler <john@sugarbit.com> - 2026-01-20 08:05 -0600
                  Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-20 19:39 +0000
                    Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-21 02:12 +0100
                      Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-21 20:21 +0000
                        Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-27 22:37 +0100
                          Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-27 22:50 +0100
                Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-20 17:11 +0100
                  Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-20 20:02 +0000
                    Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-21 08:28 +0100
                      Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-21 20:09 +0000
                        Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-27 22:45 +0100
                          Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-28 19:43 +0000
                            Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-29 04:19 +0100
                              Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-29 21:45 +0000
                                Re: A Derivation of Faraday's law from Coulomb's Law and Relativity ram@zedat.fu-berlin.de (Stefan Ram) - 2026-01-29 22:08 +0000
                                  Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-30 18:32 +0000
                                    Re: A Derivation of Faraday's law from Coulomb's Law and Relativity ram@zedat.fu-berlin.de (Stefan Ram) - 2026-01-30 19:04 +0000
                                      Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-30 19:47 +0000
                                Re: A Derivation of Faraday's law from Coulomb's Law and Relativity John Hasler <john@sugarbit.com> - 2026-01-29 17:11 -0600
                                  Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-30 01:19 +0100
                                  Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-30 18:09 +0000
                                Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-30 01:18 +0100
                                  Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-30 18:26 +0000
                              Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-30 14:09 +0100
                            Re: A Derivation of Faraday's law from Coulomb's Law and Relativity ram@zedat.fu-berlin.de (Stefan Ram) - 2026-01-29 11:54 +0000
                              Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-29 21:51 +0000
                                Re: A Derivation of Faraday's law from Coulomb's Law and Relativity ram@zedat.fu-berlin.de (Stefan Ram) - 2026-01-29 22:13 +0000
                                Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2026-01-30 01:20 +0100
                                  Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-30 18:07 +0000
                                    Re: A Derivation of Faraday's law from Coulomb's Law and Relativity ram@zedat.fu-berlin.de (Stefan Ram) - 2026-01-30 18:17 +0000
                                      Re: A Derivation of Faraday's law from Coulomb's Law and Relativity Kuan Peng <titang78@gmail.com> - 2026-01-30 18:33 +0000

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#894995

FromKuan Peng <titang78@gmail.com>
Date2026-01-30 18:26 +0000
Message-ID<s5J7bSNrxNC5tz-2MFfKE6dR7Kw@jntp>
In reply to#894987
Le 30/01/2026 à 01:18, Thomas 'PointedEars' Lahn a écrit :
> Kuan Peng wrote:
>> Le 29/01/2026 à 04:19, Thomas 'PointedEars' Lahn a écrit :
>> 
>> You think the current to be "alternating",
> 
> It is alternating.
> 
>> I think it to be direct, 
> 
> Merely an academic possibility.  In real life, a transformer transforms high
> voltage to low voltage or vice-versa because the current is an alternating
> current.
> 
My coils A and B are not those of a transformer. Just two plain coils. 
Nevertheless, Faraday’s law should work with them with a linearly 
increasing current.  

>>> Also, in general you should not think of electricity as electrons (or worse,
>>> positive charges) flowing through a conductor from one end of a circuit to
>>> the other, like flowing water.  That is NOT how it works:
>> Is electron beam an electric current?
> 
> Yes.
> 
>> Do we use Maxwell’s equations to describe its behavior? 
> 
> Yes.
> 
> Your point being?
If an electron beam is a current and Maxwell’s equations work for it. 
Then, a current in a conductor should be consistent with Maxwell’s 
equations whether
>>> think of electricity as electrons (or worse, positive charges) flowing through a 
>>> conductor 
>>>from one end of a circuit to the other,
Or  NOT. 
 
> 
> You are not in a position to make an informed judgement because evidently
> you have never studied physics.  He has, and so have I; he is correct.
> 
You are the judge 

> 
> I am not interpreting, I *know* because I have studied it.  *You* are
> interpreting because you do NOT know.  Big difference.
You are the judge 
>> The induced voltage
> 
> Voltages are not induced.
>
 You can say it. 

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#894991

FromThomas 'PointedEars' Lahn <PointedEars@web.de>
Date2026-01-30 14:09 +0100
Message-ID<10liaie$8845$1@gwaiyur.mb-net.net>
In reply to#894977
Thomas 'PointedEars' Lahn wrote:
> Kuan Peng wrote:
>> 1.	Before the current circulates in coil A, there is not a current in coil 
>> B .
>> 2.	After the current circulates in coil A, a current is induced in coil B.
> 
> In practice there is no "circulating current" as it is an "alternating"
> current to maximize the induced current.

No idea why I put "alternating" in quotes here.  An alternating current
changes direction periodically, in practice usually with a frequency of
either 50 Hz or 60 Hz, or a mixture of both (so about 50 to 60 times per
second):

<https://en.wikipedia.org/wiki/Alternating_current#AC_power_supply_frequencies>

-- 
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.

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#894980

Fromram@zedat.fu-berlin.de (Stefan Ram)
Date2026-01-29 11:54 +0000
Message-ID<radiation-20260129125256@ram.dialup.fu-berlin.de>
In reply to#894974
Kuan Peng <titang78@gmail.com> wrote or quoted:
>But each physicist attribute it different sense in his head and it is his 
>proper interpretation that makes that different physicist when predicting 
>the outcome of a same experiment using the same formula ∇ × E' = 
>-∂B'/∂t can give different result.

  Well, with that formula there really isn't much of an issue.
  There's one part in electrodynamics that's kind of murky,
  and that's the stuff tied to the radiation reaction.

|The Abraham-Lorentz formula has disturbing implications,
|which are not entirely understood a century after the law 
|was first proposed.
from "Radiation Reaction" in "Introduction to Electrodynamics"
(2013) - David J. Griffiths

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#894983

FromKuan Peng <titang78@gmail.com>
Date2026-01-29 21:51 +0000
Message-ID<jp-GeBzwkagaLDWcn8lgOF_dMUQ@jntp>
In reply to#894980
Le 29/01/2026 à 12:54, ram@zedat.fu-berlin.de (Stefan Ram) a écrit :
> Kuan Peng <titang78@gmail.com> wrote or quoted:
>>But each physicist attribute it different sense in his head and it is his 
>>proper interpretation that makes that different physicist when predicting 
>>the outcome of a same experiment using the same formula ∇ × E' = 
>>-∂B'/∂t can give different result.
> 
>   Well, with that formula there really isn't much of an issue.
>   There's one part in electrodynamics that's kind of murky,
>   and that's the stuff tied to the radiation reaction.
> 
> |The Abraham-Lorentz formula has disturbing implications,
> |which are not entirely understood a century after the law 
> |was first proposed.
> from "Radiation Reaction" in "Introduction to Electrodynamics"
> (2013) - David J. Griffiths
Electromagnetism has many paradoxes. For example, Lorentz force violates 
Newton’s third law. 

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#894985

Fromram@zedat.fu-berlin.de (Stefan Ram)
Date2026-01-29 22:13 +0000
Message-ID<law-20260129231235@ram.dialup.fu-berlin.de>
In reply to#894983
Kuan Peng <titang78@gmail.com> wrote or quoted:
>Electromagnetism has many paradoxes. For example, Lorentz force violates 
>Newton’s third law. 

  This is true. But it just means that Newton's laws have a limited
  scope. I do not deem this to be an actual paradox, because we can
  clearly see that here electromagnetism has priority over Newton.

|In electrostatics and magnetostatics the third law holds, 
|but in electrodynamics it does not.
"Newton’s Third Law in Electrodynamics" in "Introduction to
electrodynamics" (2013) by David J. Griffiths. 

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#894989

FromThomas 'PointedEars' Lahn <PointedEars@web.de>
Date2026-01-30 01:20 +0100
Message-ID<10lgtgg$2p57$3@gwaiyur.mb-net.net>
In reply to#894983
Kuan Peng wrote:
> Electromagnetism has many paradoxes. For example, Lorentz force violates 
> Newton’s third law. 

:-D

No, it does NOT.

-- 
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.

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#894992

FromKuan Peng <titang78@gmail.com>
Date2026-01-30 18:07 +0000
Message-ID<4GIriUvpholBK52mnD6el90xyqQ@jntp>
In reply to#894989
Le 30/01/2026 à 01:20, Thomas 'PointedEars' Lahn a écrit :
> Kuan Peng wrote:
>> Electromagnetism has many paradoxes. For example, Lorentz force violates 
>> Newton’s third law. 
> 
> :-D
> 
> No, it does NOT.

Please see this: 
Le 29/01/2026 à 23:13, ram@zedat.fu-berlin.de (Stefan Ram) a écrit :
> Kuan Peng <titang78@gmail.com> wrote or quoted:
>>Electromagnetism has many paradoxes. For example, Lorentz force violates 
>>Newton’s third law. 
> 
>   This is true. But it just means that Newton's laws have a limited
>   scope. I do not deem this to be an actual paradox, because we can
>   clearly see that here electromagnetism has priority over Newton.
> 
> |In electrostatics and magnetostatics the third law holds, 
> |but in electrodynamics it does not.
> "Newton’s Third Law in Electrodynamics" in "Introduction to
> electrodynamics" (2013) by David J. Griffiths. 

[toc] | [prev] | [next] | [standalone]


#894994

Fromram@zedat.fu-berlin.de (Stefan Ram)
Date2026-01-30 18:17 +0000
Message-ID<example-20260130191213@ram.dialup.fu-berlin.de>
In reply to#894992
Kuan Peng <titang78@gmail.com> wrote or quoted:
>Please see this: 
>Le 29/01/2026 à 23:13, ram@zedat.fu-berlin.de (Stefan Ram) a écrit :
>>Kuan Peng <titang78@gmail.com> wrote or quoted:
>>>Electromagnetism has many paradoxes. For example, Lorentz force violates 
>>>Newton’s third law. 
>>This is true. But it just means that Newton's laws have a limited
>>scope. I do not deem this to be an actual paradox, because we can
>>clearly see that here electromagnetism has priority over Newton.
>>|In electrostatics and magnetostatics the third law holds, 
>>|but in electrodynamics it does not.
>>"Newton’s Third Law in Electrodynamics" in "Introduction to
>>electrodynamics" (2013) by David J. Griffiths.

  Here's an example for this (taken from Griffiths):

  Assume, q1 is moving along the x axis at constant speed,
  and q2 has the charge of q1 and is moving along the y axis
  at the same speed.

  The electric force is repulsive.

  The magnetic field of of q1 at q2 points into the page,
  so the magnetic force on q2 is towards the /right/. 
  (The "page" on which the coordinate system is drawn.)

  The magnetic field of of q2 at q1 points out of the page,
  so the magnetic force on q1 is /upwards/.

  So, the force of q1 on q2 is /not/ opposite to the force
  of q2 on q1.

  (We can assume additional forces guiding the two particles to move
  along those two axes at constant speed to fulfill our preconditions.)

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#894997

FromKuan Peng <titang78@gmail.com>
Date2026-01-30 18:33 +0000
Message-ID<Ly9MucwwTzgHXk8ObCiaX4uxac4@jntp>
In reply to#894994
Le 30/01/2026 à 19:17, ram@zedat.fu-berlin.de (Stefan Ram) a écrit :
> Kuan Peng <titang78@gmail.com> wrote or quoted:
>>Please see this: 
>>Le 29/01/2026 à 23:13, ram@zedat.fu-berlin.de (Stefan Ram) a écrit :
>>>Kuan Peng <titang78@gmail.com> wrote or quoted:
>>>>Electromagnetism has many paradoxes. For example, Lorentz force violates 
>>>>Newton’s third law. 
>>>This is true. But it just means that Newton's laws have a limited
>>>scope. I do not deem this to be an actual paradox, because we can
>>>clearly see that here electromagnetism has priority over Newton.
>>>|In electrostatics and magnetostatics the third law holds, 
>>>|but in electrodynamics it does not.
>>>"Newton’s Third Law in Electrodynamics" in "Introduction to
>>>electrodynamics" (2013) by David J. Griffiths.
> 
>   Here's an example for this (taken from Griffiths):
> 
>   Assume, q1 is moving along the x axis at constant speed,
>   and q2 has the charge of q1 and is moving along the y axis
>   at the same speed.
> 
>   The electric force is repulsive.
> 
>   The magnetic field of of q1 at q2 points into the page,
>   so the magnetic force on q2 is towards the /right/. 
>   (The "page" on which the coordinate system is drawn.)
> 
>   The magnetic field of of q2 at q1 points out of the page,
>   so the magnetic force on q1 is /upwards/.
> 
>   So, the force of q1 on q2 is /not/ opposite to the force
>   of q2 on q1.
> 
>   (We can assume additional forces guiding the two particles to move
>   along those two axes at constant speed to fulfill our preconditions.)
exact

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